1. Field of the Invention
The present invention relates to a tapping valve of plastics material for transport and storage containers for liquids.
2. Description of the Related Art
DE 298 24 096.3 U1 discloses a tapping valve constructed as a flap valve or ball valve with a valve housing having an inlet connection connectable to the outlet connection of the liquid container and an outlet connection, wherein the outlet connection of the valve housing is welded to the male part of a Kamlok or quick disconnect coupling for connecting a tapping hose.
Tapping valves of the above-described type constructed as flap valves are used, for example, in liquid containers as they are disclosed in DE 195 11 723 C1; these liquid containers include a pallet-like base frame, an exchangeable inner container of plastics material with four side walls, a lower and an upper bottom, an inlet connection and an outlet connection, and with an outer casing surrounding the inner container, wherein the outer casing is constructed as a casing of sheet metal or grating having vertical and horizontal grate rods of metal.
In the flap valve described in DE 298 24 096.3 U1, the valve housing and the male part of a Kamlok coupling welded to the outlet connection of the valve housing are of a polyethylene of high density (PE-HD). This plastics material provides the valve housing and the male part of the Kamlok coupling with a limited elasticity; this elasticity is desired in the valve housing in order to achieve a tight closed position of the flap disc; however, in the male part of the Kamlok coupling, this elasticity has the disadvantage that when the female part of the Kamlok coupling, which is attached to the connecting end of a discharge hose, is tightened on the slightly elastically deformable male part by means of the clamping levers provided on the female part, it is not possible with the desired certainty to ensure a tight connection of the discharge hose.